Finally got the booster out. Did not go as smoothly as I had hoped. One of the bolts holding the master cylinder to the booster snapped, which increases this part of the project significantly. I did not intend to repair/replace the booster, but looking at what came out of it, a bit of maintenance certainly is due. not sure if I'll fix this one, or get a new unit. They're not very cheap.
I'll fabricate a tool to open it, then we'll see how it looks inside.